The present invention relates to a device for the high speed feeding of rod-like articles, such as for example cigarette filter rods, from a magazine in which there is contained a bulk supply of said articles to a subsequent processing machine, such as can be for example a cigarette making machine.
The known feeding devices usually comprise a magazine presenting downwardly inclined and converging bottom walls, forming a throat from which a single row of articles (filter rods) enters a substantially vertical (or anyhow slightly inclined) chute. In correspondence with the bottom end of the said chute there is arranged a pick-up device, usually in the form of a rotating drum presenting pick-up teeth, which picks the filter rods sequentially the one after the other as they come out of the bottom end of said chute, and conveys them for example to a transferring drum for subsequent handling operations.
In order to improve the speed characteristics of the said devices, there are known feeding devices in which at least one of the bottom walls of the magazine is subjected to vibratory movement, so as to favour the introduction of the filter rods into the throat zone and in the descending chute. According to other known type devices, one of the said bottom walls of the magazine is constructed as an endless belt which continuously moves the filter rods in a row towards the inlet or upper end of the said chute. The above devices however, present the inconvenience that the filter rod descend along the chute due to the gravity force, and therefore their speed along this chute is necessarily limited, which does not permit to drive the pick-up device arranged at the bottom or outlet end of the chute at higher operational speeds which could be attained by the cigarette maker operatively connected to the feeding device.
In order to increase the speed of the filter rods along the downwardly directed chute, it has been proposed, by the U.S. Pat. No. 4,063,633 (HALL), to provide suction means in correspondence with the bottom end of the chute, so as to draw downwardly at least the lowermost filter rod along the chute, due to the combined action of gravity and of the suction, at a resulting rate of acceleration faster than gravity. This device however present the inconvenience that, although the speed of the lowermost filter rods is remarkably increased, there cannot be ensured a constant and predetermined feeding flow of the rods to the outlet end of the chute, in correlation with the demand of the pick-up device. In fact, in the upper section of the chute the feeding speed depends on gravity (with the consequent limitations), while in the lower section of the chute there takes place an acceleration of the speed of the lowermost rods, which does not determine necessarily an increased outflow of rods from the outlet end of the chute, in the same time interval.
In consideration of the above, the present invention provides for a device for the high speed feeding of rod-like articles, such as cigarette filter rods, from a magazine, through a substantially vertical chute, to a pick-up device arranged in correspondence with the outlet or bottom end of the chute, in which the improvement resides in the fact that there are provided forced-feeding means for positively feeding the filter rods from the bottom of the magazine through the inlet end of the chute, so that the filter rods are practically pushed downwardly through the said chute at a predetermined constant speed.
According to a first embodiment of the invention, the said forced-feeding means consist of at least one endless suction belt which defines a side wall of the vertical chute and at least an adjoining portion of the bottom wall of the magazine.
According to another preferred embodiment, the forced-feeding means consist of a suction roller driven at a suitable speed and arranged in correspondence of the inlet or upper end of the vertical chute.
The above and other features of the invention and the advantages deriving therefrom will appear evident from the following detailed description of two preferred embodiments of same, made with reference to the attached drawings.